The mammalian immune system protects the host by recognizing bacteria, viruses and kinds of stuff as antigens and eliminating them through the action of the system. The immune system is roughly classified into cellular immunity and humoral immunity, and the both immune systems affect each other to optimize the immune reactions for host defense. T cells participate to play an important role in the modulation of the function of the immune system.
T cells are broadly classified into Th1 and Th2 cells. Th1 cells enhance cellular immunity and Th2 cells enforce humoral immunity. The imbalance in the Th1/Th2 ratio may cause various immune diseases. It is considered that when Th1 cells are dominant, an organ-specific autoimmune disease occurs and when Th2 cells are dominant, a type I allergy or related diseases occur. Therefore, there has been a requirement for a food, a food additive and a medicine, which are useful for realizing the potential for maintaining the Th1/Th2 balance.
References cited herein include Ina K. et al., J. Immunol. 163: 1081, 1999, Boirivant M. et al., Gastroenterology 116: 557, 1999, Watanabe-Fukunaga R. et al., Nature 356:314, 1992, Akdis M. et al., FASEB J. 17: 1026, 2003 and Guerra F. et al., J. Allergy Clin. Immunol. 107:647, 2001.
An object of the present invention is to provide a novel and safe means for inducing apoptosis of excess T cells that may cause various diseases and to facilitate the prevention and cure of a disease such as an organ-specific autoimmune disease or a type I allergy.